The announcement comes following an angry outburst by Armstrong at a Las Vegas music festival on Saturday. The 40-year-old singer stopped a song in mid-performance and delivered a profane protest against the band’s performance time allegedly being cut short, repeatedly referring to a countdown clock that read “one minute.”

Armstrong ultimately declares, “Let me show you what one f**kin’ minute f**kin’ means,” then smashes his guitar into the stage floor until it breaks, after which he stalks off the stage. Video of Armstrong’s outburst has since been widely posted online.

“Green Day would like everyone to know that their set was not cut short,” Sunday’s statement continues, “and to apologize to those they offended…” The statement concludes with, “The band regretfully must postpone some of their upcoming promotional appearances.”

Green Day is currently promoting their new album Uno, which hits retailers on Tuesday.